In January, 2004, the United States successfully launched “Spirit”, a Mars Exploration Rover, _____ a new milestone in the history of mankind.
72. At the beginning, I had some difficulty with my English, and my teacher pulled me ______.
71. Such a small man can’t _____ reach the balloon one metre higher than he.
70. These books are _____ written for those who learn how to use computer. It’s an ABC of computer learning.
69. In order to keep fit, the retired women, whether rain or shine, go _____ for plenty of exercise early in the morning.
68. Yesterday my friend and I went to the supermarket nearby. We found that there were _______ nothing worth buying.